Improvement in the manufacture of door-knobs



I. SMITH. Manufacture of Door-Knobs.

Patented April 7, I874.

WITNESSES.

R 0 M m m .dttorneys.

UNITED STATES PATENT Orrrca.

, ISAAC SMITH, or new YORK, r.

IMPROVEMENT IN THE MANUFACTURE OF DOOR-KNOBS.

Specification forming part of Letters Patent No. 149,351; dated April 7,1874; application filed August 20, 1873.

To all whom it may concern:

Be. it known that I, ISAAC SMITH, of New York city, in the county of NewYork and State of New York, have invented certain new and usefulImprovements in Manufacture of Filled Ware; and I do hereby declare thefollowing to be a full, clear, and exact descrip tion of the invention,such as will enable others skilled in the art to which it pertains tomake and use'it, reference being had to the accompanying drawings, whichform part of this specification.

My invention relates to an improvement in the process of constructingknobs, handles, 820.; and consists in first constructing the same fromthin metallic substance and afterward filling the same with any suitablematerial under pressure.

I am aware that various articles have been formed of a thin shell andfilled by the ordinaryprocess of pouring or stuffing, but not underpressure. WVhen these fillings dry or cool there is such a shrinkage ofthe material that every portion of the shell is not perfectly filled,and there is, therefore, imperfect support to the shell, which may beeasily indented and defaced. I overcome this fault and produce anarticle that can withstand severe usage without the slightest damage bymy process of filling, which is substantially as follows:

The shell isfilled, before compressing, to v such an extent that whenthe follower is forced down the material will be forced into everyinterstiee, and while yet under great pressure will harden or set;whereas, if the shell is simply filled without pressure, and then thematerial permitted to set, it will, in setting, separate from the innersurface of the shell. If a tang is to be forced into the substance inthe shell, or a spindle, as indicated in the drawings, is to beinserted, the shell must not be filled so full that the follower ineffecting the compression cannot displace enough of the material toadmit the spindle or tang.

The dies in which the shell is placed are simply counterparts of theexterior surface of the shell, and are intended merely-to furnish abacking, so that the shell will not be distorted under the compressioncaused by the the socket B, is forced down under heavy.

By this operation the filling material is displaced and pressure, asheretofore stated.

packed closely into every part of the shell A.

This invention has nothing to do with the Various and obvious ways bywhich the material is placed in the shell prior to the compressingaction of the follower. This invention begins when the material, once inthe shell, is ready for compression. In this particular instance shownby the drawing the top portion of the shell is raised, the plasticcompound in a lump placed within the lower half,

and the cap brought down upon it; but any other method of filling theshell may be employed without encroaching upon the princi ple of myinvention, which is understood to begin with the shellwhen it issufiiciently or properly filled ready for the compressing action of thefollower. I

I do not limit myself to the application of my invention to themanufacture of knobs, as any article which. can be a filled shell may bemade by my process.

WVhat I claim is The within-described process for making door-knobs,handles, &c., the said process consisting in filling the exterior shellwith suitable adhesive plastic material, which is then submitted to agreat pressure before setting, substantially as and for the purposes setforth.

In testimony that I claim the foregoing I have hereunto set my hand this19th day of August, 1873.

ISAAC SMITH.

Witnesses:

L. L. LEGGETT, EDM. F. BROWN.

A is the

